Torque converters which have a first member rotating around an axis of revolution, a second member rotating around the axis of revolution and movable with respect to the rotating first member between two angular limit positions, and coil, straight, or curved springs disposed between the two rotating members to allow kinetic energy to be converted into potential energy and, conversely, potential energy into kinetic energy when the rotating members rotate with respect to one another, if applicable with interposition of energy dissipation elements, are known. These dampers having coil springs are relatively bulky and do not offer wide design freedom for adapting, as necessary, the angular stiffness between the rotating members. Their dynamic behavior, bearing in mind centrifugal effects, is furthermore difficult to manage, especially due to friction between the springs and the walls of their receptacles.
The document FR 3 000 155 proposes to replace the coil springs with flexible blades carried by one of the rotating members of the damper, these flexible blades forming cam tracks associated with cam followers carried by the other rotating member. The relative rotational movement between the rotating members causes flexing of the flexible blades when the cam followers are displaced on the cam tracks. The profile of the cam tracks can be adapted in order to vary the angular stiffness as a function of angular deflection.
This document does not, however, teach a simple approach to determining a cam profile conforming to a desired characteristic curve, thus necessitating considerable trial and error. In addition, the proposed cam profiles are not adapted for industrial production, in particular because they lend themselves poorly to dimensional quality controls.